An organic light emitting element of an organic light emitting display (OLED) apparatus includes an anode, a cathode and an organic light emitting layer. Holes that are provided from the anode are combined with electrons that are provided from the cathode in the organic light emitting layer to generate exciton having excited state. When the exciton changes from an excitation state to a ground state, a light is generated from the light emitting layer.
The OLED apparatus has various characteristics such as high luminance, wide viewing angle, thin thickness, low power consumption, etc. The OLED apparatus has simple structure compared to other display apparatus such as a cathode ray tube (CRT) apparatus so that a manufacturing cost of the OLED apparatus is lower than that of the CRT apparatus. In addition, the OLED apparatus is a light emissive type display apparatus to display a good image regardless of the viewing angle. Furthermore, the OLED apparatus may have flexible plate that may be bent in a direction that is in substantially perpendicular to a surface of the plate.
When the organic light emitting layer is exposed to water or oxygen, the organic light emitting layer is reacted with the water or the oxygen to deteriorate electrochemical characteristics of the organic light emitting layer. In order to isolate the organic light emitting layer from the water or the oxygen, the organic light emitting layer is in a closed space. Alternatively, the OLED apparatus may include a protecting layer that protects the organic light emitting layer from the water and the oxygen.
A metal can, a glass substrate, etc., may be on the organic light emitting element to form the closed space. When the organic light emitting layer is in the closed space, a manufacturing process of the OLED apparatus is complicated, and the manufacturing cost of the OLED apparatus is increased. In addition, a thickness of the OLED apparatus is increased so that a flexibility of the OLED apparatus is decreased.
An organic material is coated on the organic light emitting element to form the protecting layer. Alternatively, an inorganic material may be deposited on the organic light emitting element to form the protecting layer.
When a molecular weight of polymers in the protecting layer is increased, a permeability of the protecting layer is increased. In addition, when the protecting layer having the polymers is formed in a high temperature, a crack may be formed in the polymers.
When the inorganic layer is directly formed on the organic light emitting element, the organic light emitting element may be deteriorated by a heat generated from the deposition process. Therefore, the layer that makes contact with the organic light emitting element is formed at a low temperature. However, when the organic layer is formed at the low temperature, the permeability of the organic layer is increased.
The organic layer or the inorganic layer may form a protecting layer of other flat panel display apparatuses such as a liquid crystal display (LCD) apparatus, a plasma display panel (PDP) display apparatus, etc., or a touch panel.